Thickeners or other viscosity-modifiers are often used in aqueous-based functional products, e.g. household products, commercial products, cleansers, disinfectants, bleaches, and the like and in personal care products, such as soaps, lotions, face creams, hand creams, toothpaste, and the like. Thickeners that have been used in these applications include such things as natural and synthetic water-sensitive organic polymers, or other water-sensitive organic substances. Also, inorganic substances, such as natural clays, refined clays, synthetic clay-like materials, silicates, and aluminates have been used. As used herein, a "functional" product is one which is applied to, or mixed with, or added to a substance which is desirably and beneficially affected by the thickener, such as cleaning solutions, bleaches, lotions, creams, corrosive fluids, oxidizing agents, reducing agents, alkali solutions, amine solutions, phenolic solutions, and chemical solutions not lower than about pH 4.5 preferably not lower than about pH 5.
Natural clays and refined natural clays may vary from one mining location to another and the performance obtained with one batch may not exactly match the performance of another batch: the color may not match and the effect on viscosity may not match. The natural clays, and even refined natural clays, may contain impurities which can produce non-uniformity among batches and may create side-reactions with other ingredients in a formulation to which the clay is added. Clays are normally anionic and can react with ingredients which are cationic, such as cationic surfactants used in hair conditioners or in cleansers and the like.
Polymers or other organic thickeners are often subject to microbial attack and may lose their effectiveness if not protected with a preservative. Polymerics often have a gooey, tacky, and/or slippery feel on the skin which is unpleasant. Some polymers do not typically have a true yield point which is required to indefinitely suspend solids. Many of the polymeric thickeners also contain functional groups which are adversely attacked by the chemicals in bleaches or other formulations, and this can cause a loss or diminishment of either the desired viscosity control or the effectiveness of the chemical.